Controlling Field-Effect Transistor Biosensor Electrical Characteristics Using Immunosorbent Assay

A method to modulate the signal of field‐effect transistor biosensors using an immunosorbent assay is described. A model system is used to show that binding of a secondary antibody, to which highly charged gold colloids are attached, to an analyte on the device floating gate can be used to induce strong electrostatic effects, which affect the device threshold voltage and source‐drain current. This process may be used for signal amplification, with the secondary binding specificity allowing for improved signal to noise ratio, which is of great importance for early disease detection.